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1、不同日粮模式对奶牛乳腺对氨基酸的摄取效率和乳腺动静脉激素变化规律的影响摘要:试验研究不同日粮模式对奶牛乳腺对氨基酸的摄取效率和乳腺动静脉激素变化规律的影响。选用经产,体况良好,体重、产奶量、泌乳天数相近的荷斯坦奶牛10头,随机分为两组,分别饲喂混合粗饲料日粮(IMF)和低精料秸秆日粮(CS2)O饲喂第21d对尾动脉和乳静脉采集血样,测定血液中游离氨基酸和激素(COR、IGF-I、HGH、LEP、INS和PRL)浓度。结果表明:(1)IMF组动脉血中COR、HGH、LEP.INS和PRL浓度分别比CS2组的高;IMF组静脉血中C0R、IGF-I
2、、HGH、LEP和INS浓度分别比CS2组的高,除HGH差异显著外,其余均不显著;两组中乳静脉中IGF-I和INS分别比尾动脉中的高。此外,HGH、INS和PRL在饲喂后2-3h达到一个高峰值,随后进行波动变化,而COR、IGF-I和LEP比以上三种激素早达到高峰值,高峰值一般出现在饲喂后l-2ho(2)IMF组奶牛乳腺对Glu和Arg的摄取率显著高于CS2组,而对Cys的摄取率呈低于CS2组的趋势且为负值;对于Gly的摄取率两组均较低,且IMF组为负值;IMF组奶牛乳腺对和支链氨基酸(Vai、lie和Leu)的摄取率均高于CS2组,但差异不
3、显著。以上研究结果表明,功能性氨基酸(Arg.Ser、Vai、lie和Leu等)和激素(COR、IGF—]、HGH、LEP、INS和PRL)在奶牛乳腺合成乳蛋白过程中起着重要作用。关键词:功能性氨基酸激素奶牛乳腺乳蛋白Abstract:ThisexperimentwasconductedtostudytheeffectsofdifferentdietsonextractionofaminoacidsandchangelowsofhormonesofarterialandvenousbloodintheMammaryGlandofDairyCo
4、ws.Accordingtotheprincipleofcloseweight,milkyieldandlactationdays,10holsteincowswhichweremultiparityandhadgoodbodyconditionswererandomlyassignedto2groupswith5replicates・Twogroups,dietswererespectivelymixedforage(IMF)andlow-concentrateandcornstover(CS2).Bloodsamplewerecollec
5、tedat21dfordeterminationoftheconcentrationsoffreeaminoacidsandhormones(COR,IGF-I,HGH,LEPandINSandPRL)inmilkvenousandcaudalarterialblood.TheresuItsshowedthat:(1)ConcentrationsofCOR,HGH,LEPandINSandPRLinthearterialbloodofgroupIMFwerehigherthangroupCS2respectively.Comparedwith
6、theconcentrationsofCOR,IGF-I,HGH,LEPandINSinthevenousbloodofgroupCS2,groupIMFwereallhigher,theHGHwassignificantdifference,andtherestwerenot.TheconcentrationsofIGF-IandINSinthevenousbloodwashigherthaninthearterialbloodoftwogroupsrespectively.Inaddition,theconcentrationsofHGH
7、,INSandPRLreachedapeakafterfeeding2to3h,subsequentlychangedbyruleofwave・However,theconcentrationsofCOR,IGF-IandLEPreachedthepeakearlieraboutonehourthanthosehormones・(2)TheextractionsofGluandArginmammaryglandofdairycowofgroupIMFweresignificantlyhigherthangroupCS2,whiletheext
8、ractionofCyswasnegativeandtrendedlowerthangroupCS2.FortheextractionofGly,twogroups